In the last year, the focus of my work has been on morphologic and immunocytochemical analyses of several focused areas of cytology. Ongoing projects include: evaluation of the morphologic spectrum of atrophy in PAP smears to identify true preneoplastic changes and describe specific cytologic patterns. In an attempt to identify and quantify the presence of IGF - 1 receptors in mesothelioma cell lines, we titered antibody to IGF - 1 receptor using a known control with different fixatives for cytospin and paraffin embedded material. We concluded that cytospins showed optimal staining at 1:5 with formaldehyde fixation. Studies of the formalin-fixed paraffin embedded cell block section showed optimal staining at 1:10. Nine mesothelioma cell lines examined for the presence and intensity of the IGF - 1 receptor revealed positive staining with intensity ranging from 1+ to 3+. In cooperation with Dr. Sandra Wolman, Medical Director of Oncor, Inc., we processed 25 cytology samples in an attempt to define and outline a method for optimal specimen processing for FISH use in cell suspensions, techniques applicable to all fresh cytology specimens which can also be used for the processing of surgical pathology aspirates and other material. We concluded all samples should be promptly processed to ensure specimen viability and triaged on an individual basis to ensure preparation of moderately cellular monolayered cytospins. Equivalent nuclear probe signals were obtained with several sample fixation methods: air-drying, 95% ethanol, methanol (Diff-Quik fixative) and Carnoy's solution. No difference was noted in the nuclear probe signals or specimen adhesion on positively charged or non-charged slides. After initial fixation, our slides remained at room temperature until FISH was performed without any adverse effects. A short digestion with proteinase K and subsequent rehybridization yielded positive results on samples that originally yielded poor nuclear probe signals.